Sleep apnea is a common sleep disorder in which a person experiences one or more pauses in breathing or shallow breaths during sleep. Sleep apnea is commonly associated with auto-retraction of the tongue resulting in a blockage of a patient's airway during sleep. This blockage of the airway by the tongue frequently leads to loud snoring or sleep apnea. Numerous oral devices have been used to attempt to solve this problem.
The basic design of these devices is to hold the movable lower jaw in a forward position while the user sleeps by utilizing a lever system designed to push against the immovable upper jaw. Since the tongue is attached to the front section of the lower jaw, repositioning the lower jaw forward acts to also reposition the tongue forward which in turn opens the patient's blocked airway allowing the patient to breathe freely while sleeping.
Examples of other devices which seek to prevent sleep apnea and/or snoring are shown in U.S. Pat. Nos. 5,427,117; 5,537,994; 5,566,683; 6,155,262; and 6,516,805, issued to Thornton. These devices share several common features, including upper and lower arches which cover the patient's teeth, and a downwardly extending post, extending from an inner side of the upper arch to contact the lower arch on an inner portion thereof. This contact holds the lower jaw at a forward position relative to the immovable upper jaw. One drawback of these designs is that the downwardly extending post or hook tends to obstruct the user's tongue as the post is positioned on the inside of the upper and lower arches, in the palatal region of the user. This obstruction of the user's tongue reduces the potential for the effectiveness of the appliance insofar as the idea is to pull the tongue forward and create a clear open space for the tongue.
Some of these devices also include an adjustment mechanism, to adjust the position of the lower arch relative to the upper arch. The adjustment mechanism presents another drawback to these devices; as such a mechanism is bulky. This bulkiness impedes the user's lips from closing properly which results in the user developing dry mouth and/or excessive drooling during sleep. This is counter-productive to normal sleep.
U.S. Pat. No. 6,155,262 issued to Thornton attempts to address the issue of the bulky adjustment mechanism by converting the device from an adjustable dental device to a non-adjustable dental device. While this action reduces the bulkiness to the lips, the device is no longer adjustable. The disadvantage to the non-adjustable design is that over time, some users' connective tissues that make up their jaw joints and their jaw musculature lengthen, making it necessary to reposition the user's lower jaw further forward. Therefore, in some cases, the non-adjustable appliance becomes progressively less effective over time by causing the user's connective tissues to lengthen and again allow the tongue to fully collapse into the user's airway.
Another patented oral device is disclosed U.S. Pat. No. 6,305,376 issued to Thornton. One drawback of this device is that its adjustment capability is also limited. In some cases, an end point to its adjustment capability is reached prior to meeting the needs of pulling the lower jaw far enough forward with respect to the upper jaw. This results in an ineffective device, in that the user's tongue remains collapsed in the user's airway. In other cases, this device becomes ineffective slowly over time due to the gradual lengthening of the connective tissue of the user's jaw joints and jaw musculature, respectively. This occurs due to the nightly repetitive forward positioning of the user's lower jaw. In these cases, the tongue slowly returns to once again block the user's airway.